Applicant hereby incorporates by reference the following patent applications in their entirety:
1) U.S. application Ser. No. 08/238,090, filed May 4, 1994, by Robert C. Meier now abandoned;
2) U.S. application Ser. No. 08/177,738, filed Jan. 4, 1994, by Robert C. Meier now abandoned;
3) U.S. application Ser. No. 08/147,766, filed Nov. 4, 1993, by Robert C. Meier now abandoned;
4) U.S. application Ser. No. 08/073,142, filed Jun. 4, 1993, by Robert C. Meier now abandoned;
5) U.S. application Ser. No. 08/058,905, filed May 6, 1993, by Robert C. Meier now abandoned;
6) U.S. application Ser. No. 07/769,425, filed Oct. 1, 1991, by Meier et al. now abandoned; and
7) PCT Application Ser. No. PCT/US92/08610, filed Oct. 1, 1992, by Meier et al.
The present invention relates to a wireless and wired communication network used to maintain communication pathways among wireless communication devices and remote stations. As is well known, wired local area networks (xe2x80x9cLANsxe2x80x9d), such as ethernet utilizing coaxial or twisted pair cabling (xe2x80x9cwiringxe2x80x9d), provide communication among remote stations, such as personal computers, which are commonly wired to a wired LAN. Hereinafter, a wired LAN is referred to as a xe2x80x9cwired subnetxe2x80x9d. To maintain communication beyond the wired range of ethernet, for example, bridging devices are employed to route information between one wired section of ethernet to another wired section. The bridging devices forward communication from one side of the bridging device onto the other, and vice versa. Smarter bridging devices are also known which keep track of the location of the remote stations so that forwarding only occurs when necessary.
As is also well known, in typical wireless communication networks, wireless communication generally occurs directly between two or more wireless terminals. To overcome transmission range limitations, such wireless networks have included wireless relaying transceivers to relay received communication, extending the range at which communication can be maintained. However, depending on the mode of wireless communication, many wireless relaying transceivers may be needed to adequately serve the network requirements.
In earlier wireless communication systems, the wireless relaying transceivers were also used to manage communication among a variety of wireless communication devices. Such relaying transceivers have been called base stations. The base station were typically connected directly to a host computer through multi-dropped connections to an ethernet communication line. To communicate between a wireless communication device and a host computer, in such a system, the wireless communication device sends data to a base station, and the base station passes the data along a hard-wired (xe2x80x9cwiredxe2x80x9d) link to the host computer.
In order to cover a larger area with a wireless communication system and to take advantage of the de-regulation of the spread-spectrum radio frequencies, later-developed wireless communication systems are organized into layers of base stations. As in earlier wireless communications systems, a typical system includes multiple base stations which communicate directly with wireless terminals and the host computer.
In such wireless networks, difficulties often arise in maintaining the integrity of wireless communications. The wireless communication network must be able to handle both wireless and wired connectivity, efficient routing of data information, wireless communication device mobility, and interference from many different sources.
Customarily, wired local area networks support wireless communication devices that occupy fixed locations. Message traffic to and from such devices are routed via paths that do not change with time. Absence of a communication link to a device reflects a fault condition, i.e., a breakdown in some network component.
Thus, one object of the present invention is to route data through a wired and wireless communication network efficiently, dynamically, and without looping.
Another object of the present invention is to make the routing of data transparent to wireless terminals and remote stations located on IEEE 802.3 type subnets.
It is a further object of the present invention for the network to be capable of handling wireless communication device mobility and lost network nodes with minimal impact on the entire data communication system.
It is a still further object of the invention to allow wireless mobile computing devices, a type of wireless communication device, to move freely within wireless networks consisting of many relay nodes while transparently maintaining network connectivity with a plurality of wired subnets.
The present invention solves many of the foregoing problems using a communication network comprising two wired subnets, a wired access point connected to each of the subnets, and a plurality of intermediate wireless access points. The plurality of intermediate wireless access points provide a wireless pathway between the wired access points connected to the two subnets. Together, the two wired access points and the plurality of intermediate wireless access points form a spanning tree which interconnects the two subnets.
In another embodiment of the invention, the network may also comprise a plurality of terminal nodes which utilize the wired access points and the plurality of intermediate wireless access points to communicate on the network.
In a further embodiment of the invention, the network may also comprise a remote station attached to each of the two wired subnets. The wired access points and the plurality of intermediate wireless access points maintain communication connectivity between the two remote stations. In addition, the network may further comprise a wireless communication device which utilizes the two wired access points and the plurality of intermediate wireless access points to communicate with the two remote stations.
In a still further embodiment, the network may also comprise a third subnet and a third wired access point connected thereto. The third wired access point participates in the spanning tree, and, along with the other two wired access points and the plurality of intermediate wireless access points, communicatively interconnects the three wired subnets. The network may also comprise a plurality of wireless communication devices which utilize the three wired access points and the plurality of intermediate wireless access points to communicate with the three subnets.
The full details of the subject invention will become apparent from the following detailed description taken in conjunction with the drawings.